Field emission devices and addressable matrices of field emission devices are known in the art. Prior art methods for fabricating these field emission devices typically involve the independent fabrication of an anode plate and a cathode plate. In the final packaging steps of the device, the anode and cathode plates must be accurately aligned. Separate fabrication of the anode and cathode plates has many disadvantages. One problem involves contamination of device elements when the cathode and anode plates are brought together for alignment. Another problem is the difficulty of the alignment itself.
A well known electron emissive structure used in field emission devices is a conical emitter generally referred to as a Spindt tip. The schemes for making Spindt tips are complex and costly. They also limit the configurations of the Spindt tips with respect to the electrodes of the device. Typically, the distance between the Spindt tips and the electron-receiving anode has a minimum value. This minimum distance is required to prevent arcing between the anode and other electrodes. This results in excessive voltage and power requirements.
Another disadvantage with this minimum distance is that the electrons emitted at the emissive structure must travel a greater distance to reach the anode. When the device is used in a field emission display, the greater travel distance results in larger spot sizes at the anode. Adequate resolution and color purity necessitate a small spot size. To provide the smaller spot size, focusing electrodes are commonly added to the device. However, these additional elements add expense and complexity to prior art processes.
Field emission devices also require the inclusion of gettering material for the removal of gaseous contaminants. Prior art getter configurations add undesirable weight and volume to the device. In one prior art scheme, a backplate is added behind the cathode plate to form a plenum for housing the getter. In this prior art configuration, the additional backplate adds substantial weight to the device.
Thus, there exists a need for a method for fabricating a field emission device that allows integrated fabrication of the anode and cathode elements. There further exists a need for a method for fabricating a field emission device that is less complex and that permits greater design choice with respect to the configuration between the emissive structures and the electrodes of the device. There also exists a need for a getter configuration that reduces the weight of the device.